Voiceover: Now, we’re not into ruining your holidays, but we do want to arm you with the knowledge you need to look after yourself. So, we’ve taken creepy crawlies expert Dr James Logan out of the lab and onto the beach to see if tourists can recognise one of the world’s most prolific parasites.
Dr James: What do you recon this is?
1st Holidaymaker: Maybe something from a horror movie?
2nd Holidaymaker: It looks like a vegetable. You know, like a carrot.
3rd Holidaymaker: A penis.
4th Holidaymaker: A finger.
Voiceover: This is actually a hookworm and its estimated 700,000,000 people have them living in their stomachs.
Dr James: When you get infected with them, they enter through the skin. And once they are in there, they travel in your blood through your heart to your lungs. And then you actually get a cough and cough them up into your mouth and then swallow them down to your intestine where they then attach.
5th Holidaymaker: It’s not contagious is it?
Voiceover: Hookworm larvae live both in contaminated pooh and in water droplets on the edges of leaves. And if you brush past or tread on them with your bare skin they will find a way into your body.
Dr James: The best thing you can do when you’re abroad is make sure you wear footwear, flip flops or whatever, and put your towel down when you sunbathe.
5th Holidaymaker: Ok.
Voiceover: And now here comes an experiment you definitely shouldn’t try at home. He’s at the London School of Hygiene and Tropical Medicine where Dr Quentin Bickle is helping him explain what these worms can do by infecting him with 50 hookworm larvae.
Dr James: So these actual worms are going to be inside my body.
Dr Quentin: Right.
Dr James: Right, let’s take a look. Oh wow, jeez. Right, ok, so there is loads of them there.
Voiceover: He’s taking part in a monitored scientific experiment and they’re hoping to achieve a world first by finding out exactly how the hookworm penetrate the skin and follow their incredible journey through the body. Dr Quentin Bickle and his team have lined up a special scanner that can see through the top layers of Dr Logan’s skin, before placing a water droplet containing 50 hookworm larvae onto his arm.
Dr Logan: Now, are they going to go into my skin, like, straight away or is it going to take…
Dr Quentin: Well, that’s one of the things we don’t really know so let’s just see (looks at screen). There it is.
Dr James: Here’s some over here, look.
Dr Quentin: Yeah, yeah, yeah.
Voiceover: The wriggling worms seen on the screen are still within the water droplet and Dr Logan should feel a stinging sensation when they penetrate his skin.
Dr James: Every now and again I feel a little sort of niggle on my skin. I am just wondering whether that is one going in or not.
Dr Quentin: (Examines and point to screen) It’s looks like we can only see the tail end now on the outside on the skin surface and the rest of the body is already inside of the superficial skin layer.
Dr James: Oh my goodness!
Voiceover: It’s taken just over 3 minutes for the larvae to enter Dr Logan’s body. And to get in that quickly the hookworms are probably using an enzyme to break down the skin and create a tunnel in to the blood stream.
Dr Quentin: (Pointing at screen) There is a suspicious mass.
Dr James: There is movement. There is movement there.
Dr Quentin: There is movement. It’s unusual movement.
Dr: The larvae are right there about a quarter of a millimetre into the skin.
Dr James: These worms are going to make an incredible journey through the body to the intestine. So they have got a big road ahead of them, really.
Voiceover: It will take at least seven days for the hookworms to reach Dr Logan’s intestines.
Dr James: Who wants to give me a hug? Anyone? No?
Voiceover: Once he’s left the lab, Dr Logan starts recording video diaries to explain exactly how the hookworms are affecting him as they travel through his body.
Dr James: I do have a little bit of a rash on my arm and it is a bit itchy.
Voiceover: He’s doing this so we all know what to watch out for. And the first sign is a rash where the hookworms enter the skin. Next he gets a cough as the worms are hacked up from his lungs and swallowed into his stomach.
Dr James: I have woken up to these weird stabbing pains in my stomach. If they are there, then it’s basically the adults that are attaching to my stomach. I don’t think I’m going to have a very good night’s sleep. The larvae actually enter through the skin and then travel to heart and then the lungs where they are coughed up into the throat and then they make their way down into the intestine and they stay there as adults sucking our blood.
Voiceover: It’s month two of the infection and the bloodsucking worms are unsettling Dr Logan’s stomach.
Dr James: I have got up because I have stabbing stomach pains again. I have felt sick pretty much the entire day, um, and I still feel sick.
Voiceover: After 55 days it’s time to visit a gastroenterologist at the Nuffield Health Wessex Hospital to take a closer look at what’s upsetting his guts.
Dr James: I think I probably had one of the worst night’s sleeps of my entire life last night, with horrible stabbing stomach pains, which is something that I’ve never actually felt before.
Voiceover: Dr Praful Patel can give Dr Logan a worm’s eye view of his intestines.
Dr Praful: You are going to swallow this (hold up tablet). This is a little camera in a pill.
Dr James: Right.
Dr Praful: As it goes down into the stomach and just beyond the stomach, we’re going to see the worms.
Voiceover: Special sensors designed to pick up radio signals from the camera are attached to his chest and recorded electronically.
Dr James: Here goes (swallows camera). I have a camera inside me. How strange.
Voiceover: A brief walk aids digestion. And within an hour the hookworm’s trail of destruction comes into view.
Dr Praful: You can see that red area there. This is where the hookworm has attached its head.
Dr James: Yeah, it looks pretty nasty!
Dr Praful: Although this is clear evidence of hookworm being present, we haven’t found any yet.
Dr James: They are quite difficult to find because they’re translucent.
Dr Praful: That’s right. As you can see there is quite a lot of redness here and further down. As I scroll…Oh! You can see… can you see this?
Dr James: It is, look! (Gestures to computer screen) That is definitely a worm isn’t it? And it’s full of blood as well.
Dr Praful: That’s definitely a worm.
Dr James: That’s incredible! That feels weird.
Dr Praful: It’s about a centimetre and half long.
Dr James: Yeah, and it’s really inflamed all around there. Is that another one there?
Dr Praful: Yes, there’s another one there.
Dr James: The head end is clearly up there, attached to the stomach lining with those teeth. Look how red it is around there as well. No wonder I have been having so much pain! It’s also a little bit gross.
Voiceover: Its day 60 of his infection and Dr James is back at the London School of Hygiene and Tropical Medicine to see what impact the hookworms are having on his health.
Dr Quentin: So now we are going to look at the blood that was taken from you before you were infected with this.
Dr James: Ok.
Dr Quentin: The first thing we are looking at here is a cell called an Eosinophil, it’s a very potent cell in the immune system.
Voiceover: Eosinophil blood cells are an important part of the body’s immune system which is the mechanism within us that fights infection. Eosinophils are associated with fighting parasites like hookworm. Normally they make about 1% of our blood. But people like Dr James who are infected with hookworms usually start producing more of these cells.
Dr Quentin: We can see two Eosinophils next to each other which is clearly much more abundant that we saw in the other field, just in the first field we look at.
Dr James: Oh, you can yeah. If I just move it around a bit you can see some more there as well.
Dr Quentin: So this shows the proportion of Eosinophils in your blood has now gone up 15 fold.
Dr James: 15 times more? So my entire blood in the whole of my body has changed.
Voiceover: And Dr James’s new blood could actually make him healthy. Extra Eosinophils not only fight infection, but new research suggests that they might also improve the symptoms of some allergies.
Dr James: It is quite surprising really, isn’t it, that things like asthma and irritable bowel disease can actually, essentially, be cured. Or at least the symptoms can be reduced. I suffer from some stomach problems so, certain foods I just can’t eat, it makes me very ill. So I’m really interested to find out whether doing this is going to have any effect on that.
Voiceover: Dr James hopes that his new stronger blood might be better equipped to fight an allergy he has suffered with his whole life, a food intolerance to bread.
Dr James: One thing in particular that’s guaranteed to make me feel ill is pizza and garlic bread (eats pizza) that tastes so good. I might regret it later though.
Voiceover: Normally, a pizza feast would lead to an episode of Logan’s runs, bellyache and diarrhoea. But, 18 hours later, Dr James newly strengthened immune system seems to have held out.
Dr James: I slept the entire night. I had a brilliant night’s sleep and today I feel absolutely brilliant. So, maybe the worms are actually having a good affect on my body and I’m able to eat things like bread which is great.
Voiceover: After 60 days of living with hookworm to show us their incredible journey, what symptoms to look out for and to help the medical teams understand this munching critter, Dr Logan’s finally decided it’s time to get rid of them by simply taking a tablet which can be prescribed by a doctor either when you’re abroad or when you get home.
Dr James: I have decided that the worms are going to have to go. I just can’t live with the symptoms or the stomach pains. And all I need to do is very simply, take a little pill. Well, here goes, goodbye hookworm.
Voiceover: The chemicals in the pill will kill the hookworm and clear Dr Logan’s intestines in just 3 days.
Dr James Logan decided to let hookworms burrow their way into his bloodstream, and all in the name of scientific discovery. The worms go on an amazing journey through his body, and here you can see an extended video of the experiment.
Below are some facts and figures about the microscopic hookworms that Dr Logan allowed to infest his gut.
Hookworms: A Fact File
The hookworm is an intestinal parasite. Adult worms live in the small intestine, but not before embarking on a long and complex journey.
How Do Hookworms Spread?
Hookworm eggs are passed in the poo of an infected person. If an infected person defecates outside (near bushes, in a garden, or field) or if the faeces from an infected person are used as fertiliser, eggs are deposited on soil. They then mature and hatch, releasing microscopic larvae that penetrate the skin of humans. You can pick up a hookworm infection by walking barefoot on contaminated soil or by brushing past foliage with droplets of water containing the larvae.
The Remarkable Journey of the Hookworm
Once the hookworms are inside your body, they travel in the blood through your heart to your lungs. They penetrate the lungs and travel to your throat where they are coughed up and swallowed. Once in the intestine, they mature and become adults (around 1cm long). They attach to the intestine and feed on blood.
Once the worms enter the skin an itchy red rash appears. Many people have no symptoms whatsoever, but those with heavy infection may have abdominal pain, diarrhoea, loss of appetite, weight loss and anaemia. The development of children can be affected.
Risks, Prevention and Treatment of Hookworms
Do not walk barefoot in areas where hookworm is common and where there may be faecal contamination of the soil.
People living in areas with warm and moist climates and where sanitation and hygiene are poor are at risk of hookworm. High risk groups are young children.
Hookworm infections are generally treated for 1-3 days with medication prescribed by a health care provider. Iron supplements may be prescribed if you have anaemia.
The EB team would like to thank:
Dr Quentin Bickle
London School of Hygiene and Tropical Medicine
Dr Daniel Woods
Dr Carsten Flohr
St John’s Institute of Dermatology, King’s College University of London
Dr Praful Patel
Nuffield Health Wessex Hospital
Dr Ron Behrens
Hospital for Tropical Diseases in London
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